The Descendant
by AnIdiotsAccount
Summary: In one universe, Harry Potter saw a purple star shaped crystal in his trust vault, but ignored it. In this one, he went over and picked it up. AU.
1. Chapter 1

**A/N: This is my first fanfic on this site ever! This will be a Harry Potter/ Terraria xover, so expect elements from Terraria, and OP!Harry. Sorry, if this isn't your cup of tea, but whatever.**

 **IMPORTANT: I expect that you have played Terraria before, and read the HP books, because there will be a lot of spoilers.**

 **Disclaimer: I do not own Terraria, or Harry Potter. I wish i did though.**

 **Chapter 1: The Descendant**

Harry Potter had just arrived at his vault. He had thoroughly enjoyed the mine cart ride down to his trust vault. Hagrid had left though, saying he needed to do Hogwarts business. Harry enjoyed watching the vault door open, but the things inside was the best part in Harry's opinion. There were mountains of gold, and various items. The thing that caught his eye the most was the crystal that was on a pedestal. It was purple, and shaped like a star.

Harry strode over to it, and admired the color. It was about as small as his fist. He was entranced with it, and reached out to grab it, but instead it disappeared into dust, and flew straight at him. He fell back surprised by it, but then promptly passed out, as the dust combined with him, and funneled knowledge into his head.

…

…

…...

Harry woke up several minutes later. He remembered about the crystal thing. _The mana crystal_ , his mind supplied. He was surprised; as he was sure he had not known about it previously. It had filled his mind with a vast amount of knowledge. He know knew that it was meant to only increase his magic capacity a little, but instead, a hero of old, known as the Terrarian, had pumped it full of its own magic, and all of its knowledge.

Harry now knew that the hero defeated a being known as Skeletron, a being that gave even Merlin trouble. He knew that he defeated the eye of a god. He knew that he defeated the guardian of hell, the Wall of Flesh, and unknowingly released spirits of light and dark onto the world. He knew of the three beings made of metal, Skeletron Prime, the Twins, and the Destroyer. Harry now knew that the hero even defeated a plant god of sorts, and a god of humanity's own making.

Most of all though, Harry now knew that the hero defeated a god, and the person who summoned the god. Harry now knew of all the adventures of his ancestor, and of the magic his ancestor had cast. They were in tomes located at the bottom of Gringotts, in the most secure vault in the bank. His ancestor had made a contract with the goblins long ago that his heir would be able to access it no matter what. In that vault contained the tomes his ancestor learned from, the glove he used to store his weapons, and the legendary blade, the Terra Blade.

Harry soon snapped out of it and got right back to business. He wanted to follow in the footsteps of his ancestor, and the best way to do that was to learn the magic they used, and to use their own blade. He watched his ancestor's battles, so he was sure he could use the blade. Harry quickly gathered up 66 galleons, and left the vault. He then went up to Griphook.

"Um, I would like access to the vault of my ancestor, and as the contract states, I will be able to enter it now." Harry said nervously. Surprise flickered over the goblins face before returning stoic.

"Very well, get into the cart." The goblin said. Harry quickly scurried over, before hopping in. The goblin then pulled the lever, and soon they were off, going deeper into the bank, before reaching a very hot point. Harry was sweating up a storm because of the heat.

Soon, they came to a stop, in front of an ordinary looking door. Harry knew that there was a bunch of traps set up in front of it, and Harry knew the way to stop them. He then walked over to the wall directly to the right of the door, and pressed his hand to it. He channeled magic into it, and soon many runes started lighting up. He stepped back, and walked over to the left of the door, and then put his hand on the wall again. He felt several drops of blood drip out of his hand, as more runes started to glow. Then, he walked over in front of the door, and a light was shot at him. After several moments, it disappeared, and he simply walked over to the door, and pushed it open.

He stepped into the room, and his eyes quickly scanned the area. There were bookshelves to the left of him. To the right of him were many sets of armor. In the middle of the room were the Terra Blade, its scabbard, and a glove next to it. He immediately went up to them, and picked up the scabbard and glove first. He slipped the glove onto his hands, and felt it pulse with magic slightly. He picked the Terra Blade up, and put it into the scabbard. Soon, the sword pulsed, and Harry felt a connection with it. He shrugged it off for the moment.

Harry soon walked over to the bookshelves, and found many tomes. He was looking for the ones about the glove, how to wield a sword (he was sure he could wield one, but one couldn't be too sure), and the book of magic his predecessor had written. It contained many powerful spells, and he had seen them first hand. He wanted to cast them with his own magic.

He had spent one hour sorting through the many books, but soon found the three books he wanted. The one Harry jumped at was the book of magic. It had taken him the longest time to find it, but he persevered. Harry opened the book of magic first, and the first spell he came across was known as the "Water Bolt." It explained that all he had to do was imagine a ball of water flying out of his hand, but it had to be enforced by his magic. Harry spent two hours, and had only managed to put out a small ball of water, but it didn't go anywhere. It just fell on the floor. He was frustrated. He knew the spells would take a long time to perform, but he was getting impatient. It will be worth it, he told himself, it will be worth it. Harry repeated that as a mantra to keep himself going.

 **A/N: WHOOOO! First chapter down. Many more to go. Anyways, if any of you liked this, pleases favorite, follow, and leave a review. I am also going to put out there that if any of you would like to rewrite this chapter or any other, PM it to me, and I'll see if I like it. Anyways, see ya later!**


	2. Chapter 2

**A/N: We are now on the second chapter! I'm going to be assuming that Harry returned to his relatives on the 1st of August, because if Hagrid arrived on his birthday, then they slept, I figured it would be the first of August. They went shopping, and then returned him to his relatives. Harry is going to be able to use mana, because when I said "increase magical capacity," Harry only thinks that, so mana powers spells like the Water Bolt, Lunar Flare, etc, and magic powers spells like Expelliarmus, Stupefy, etc. Sorry if that seems kind of like a crappy way for Harry to be able to practice spells, but whatever. I also buffed the mana spells up by a lot. Anyways, enjoy!**

 **Disclaimer: I do not own Terraria, or Harry Potter. I wish i did though.**

 **Chapter 2: The Last Month**

Hagrid had just dropped Harry off in front of his relative's house. When he entered it, his cousin Dudley was terrified of him, and he couldn't stay in the same room. His aunt and uncle didn't speak to him at all, and hadn't forced him to do anything. They just ignored him, even if he was right next to them. Harry liked the fact that he now actually had a room, and not just a cupboard.

Harry went up to a forest that was close, and hid him from the view of the neighborhood. Harry then started to try and form a ball of water, and after several hours, he could now summon a ball of water, and keep it there for 5 minutes. When he tried to fire it off in a direction, it just evaporated in his hands. He then summoned the water and kept it there. He started to slowly push mana into it, and instead of blowing up, it started to drift forwards. He pushed a medium size amount of mana, and it shot off, and crashed against a tree. It only wet up the tree.

Harry flipped to the next page of the book about the spells, and found that after being able to form a ball of water, he had to surround it in electricity. Harry was exhausted from the amount of mana he had cast, and decided to go back into his relative's house. He also felt like he was being watched, but he shrugged it off. He then went up to, the room that was now his, and jumped into it. He closed his eyes, and several moments later, he fall asleep.

Two weeks had passed, and Harry had not gotten any farther along with casting the Water Bolt yet. It frustrated him to no end. He tried multiple times to surround it the ball of water with electricity. Then one day, he thought of a new method to use. Instead of creating one thing first he would do it separately. Harry summoned forth a ball of water, and then started to surround it with electricity slowly. The method was successful, as it did not blow up in his face.

After several hours of practicing the new method, Harry could now summon the ball of water, and surround it in seconds. Now the only part left was to force it forward with a lot of force. A low amount would cause it to just dissipate, a large amount would cause it to blow up in his face, and a medium amount would only push it forward slowly. He needed to channel a medium to large amount of mana to send it forward. It took many attempts, but after a long while, Harry got the perfect amount needed.

Harry summoned a ball, and sent it flying forwards. He watched with glee as it opened a hole straight through the tree, before ending. It was about the size of Harry's fist. He then pulled out the spell book, and flipped to the next spell. It was called the Scythe of the Demons. The spell summoned multiple scythes that could cut down many things. In the description, it said that this spell was found from hell. Harry sighed. This was going to take while.

* * *

Two more weeks passed, and Harry had been able to summon half of a scythe. It had taken him a lot of concentration on making the scythe solid, and making it sharp. He aimed the scythe at a tree, and cut it was cut only halfway through, before the scythe dissipated. Harry had tried many things like making the scythe solid first, and then sharpening it, but it would just blow up. He tried building it up slowly, but that didn't work either. So he settled for having to make it all at once. It had taken him a long time for it work, but he managed it eventually. Harry then used the scythes to cut down trees, and to make a shelter big enough for him. He made it twice his height, and three times his body lying down. Inside it was a table, a chair, a lantern, and a bed.

He also started to practice using his glove. Apparently it could be used to store items in it, and only two could be out at a time. There were already some things inside it such as an axe which he also used to make the shelter. It also had a staff of some kind, and when he checked one of the books, it was apparently called the Stardust Cell staff. It could summon cells to fight for him, so he put it off for now. Harry then found out that he could put the Terra Blade in it, and away it went.

 **On the last day of August Harry thought he'd better speak to his aunt and uncle about getting to King's Cross station the next day, so he went down to the living room where they were watching a quiz show on television. He cleared his throat to let them know he was there, and Dudley screamed and ran from the room.**

" **Er – Uncle Vernon?"**

 **Uncle Vernon grunted to show he was listening.**

 **"Er – I need to be at King's Cross tomorrow to – to go to Hogwarts."**

 **Uncle Vernon grunted again.**

 **"Would it be all right if you gave me a lift?"**

 **Grunt. Harry supposed that meant yes.**

 **"Thank you." (Excerpt from page 89, Harry Potter and the Sorcerer's Stone.)**

Harry turned, and left the room. He went up to go and pack up his supplies, and double checked to see if he had the books and his ticket. He had gotten the ticket from Hagrid, and it was for "Platform 9 3/4" apparently. He also looked for his wand, and found it. It was 11'', blackthorn wood, and the hair of a Wyvern, a mystical creature of the skies. It was a creature that either had completely pure soul, or a completely dark soul. Harry then turned the lights off, and jumped into the bed, and was asleep within minutes.

* * *

 **A/N: AAAAAND CUT. There we go. FYI, all the magic spells cast with books and rods will be converted into spells, like the Last Prism will become Prismatic Death for the spell, so… Yeah. I know it sounds really cheesy but I can't think of good names for it. Thanks for all the reviews already! I will gradually add more combat to the scene, and if you are worried that Harry is advancing to fast with the spells, that is because those spells are the first two. As we go along, the spells will become significantly harder for Harry to cast. Things like the Nebula Blaze or Nebular Arcanum will be for year 4. The Moon Lord spells will be years 5 to 7.**


End file.
